1. Field
The following description relates to user activity recognition technology. For example, a technique is described to recognize a user's activity in real time regardless of how a user contains a mobile terminal.
2. Description of the Related Art
With high-performance and high density integration of mobile terminals, such as smart phones, various kinds of physical or logical sensors are installed in mobile terminals. The sensors are evolving to generate various kinds of information in order to improve users' convenience. Recently, many mobile terminals include sensors, such as a global positioning system (GPS), an ambient light sensor, an acceleration sensor, a Gyroscope, a magnetic field sensor, and other similar sensors.
As a result, a technique of recognizing a user's physical activity using an acceleration sensor, which is generally called a user activity recognition technique, has been introduced. The purpose of the user activity recognition technique is to correctly recognize the user's various physical activities, for example, walking, running, going up/down the stairs, etc. in order to apply the recognized activity to various technical fields.
In addition, in order to effectively utilize the user activity recognition technique, it is necessary to recognize a user's activity in real time, regardless of a current holding of a mobile terminal. For example, regardless of whether the user is holding the mobile terminal in on hand, a pocket, or a bag, it is necessary to recognize the user's activity in real time to effectively utilize the user activity recognition technique. Accordingly, studies of a technique to correctly recognize a user's activity in real time regardless of how the user is containing the mobile terminal have been conducted.